This invention relates to a cowling structure for a marine propulsion engine and more particularly to an improved protective cowling for the power head of an outboard motor.
As is well know, it is the normal practice in outboard motors to contain the powering internal combustion engine in a protective cowling which will insure that the engine and its auxiliaries do not become wet and subject to corrosion. However, it is also necessary to provide atmospheric air to the engine for its combustion. A wide variety of air induction systems have been proposed for outboard motors which serve the main purpose of providing copious air flow to the engine for combustion but also for separating water from the inducted air so that the water cannot be drawn with the inducted air into the interior of the protective cowling where it could contaminate the engine and cause corrosion and other problems.
However, the types of air ducts proposed previously have required at least one portion that has a relatively small effective opening area so as to reduce the emanation of noises from the engine back to the atmosphere. When such small openings are provided, the water which may be entrained in the air tends to condense on the surface surrounding the opening. The restricted opening causes the air flow to accelerate and thus the condensed water is again swept back into the air stream and can find its way into the protective cowling. Thus, it is necessary to provide some drain in the lower portion of the protective cowling that permits water to drain from the area around the engine.
In addition to these problems, the protective cowling has been formed with a labyrinthine type of construction so as to cause the air flow to have to turn through several directions so as to further assist in water separation. However, these types of devices further cause the likelihood of condensed water to be trapped in the protective cowling and again swept into the air stream. In an addition, these complicated configurations are very expensive to manufacture and/or require multiple pieces for the protective cowling.
It is, therefore, a principal object to this invention to provide an improved protective cowling structure for an outboard motor.
It is a further object to this invention to provide an improved and simplified air inlet system for an outboard motor protective cowling which will separate water from the inducted air and which will also permit the separated water to drain away from the interior of the protective cowling and back to the atmosphere.
It is a further object to this invention to provide an improved and simplified air inlet device for the protective cowling of an outboard motor.